Gc\Document\Collection::getAvailableDocuments PHP Method

    public function getAvailableDocuments()
    {
        $rows = $this->fetchAll($this->select(function (Select $select) {
            $select->where->equalTo('status', Model::STATUS_ENABLE);
            $select->order('sort_order ASC');
            $select->order('created_at ASC');
        }));
        return $rows;
    }

 /**
  * Generate Xml accessor
  *
  * @param Request $request Request
  *
  * @return string
  */
 public function generate(Request $request)
 {
     $collection = new DocumentCollection();
     $documents = array();
     $rows = $collection->getAvailableDocuments();
     foreach ($rows as $row) {
         $documents[] = DocumentModel::fromArray((array) $row);
     }
     return $this->generateXml($documents, $request);
 }